Dear Lifehacker,
I've heard it's bad to shut down your computer every night. Is it really better to leave it on all the time? I have a high-end machine and want to take care of it but I don't know the best way to do that.

Sincerely,
Puzzled by Power

Dear PbP,
We're not sure how it all started, but the idea that it's harmful to shut your computer down every night is a myth. Unless you shut it down incorrectly (e.g. ripping out the power cable and laughing maniacally), there's really nothing to worry about. In fact, shutting down your computer every night offers a few advantages. First and foremost, it won't draw as much power when off. Additionally, you don't have to remember to turn off the sound each night so it doesn't wake you up with an unexpected alert. That said, keeping your computer powered on overnight has advantages as well. An always-running computer can act as a server and handle tasks while you're sleeping. Whether you shut down regularly or keep your computer running indefinitely really depends on your needs. Let's take a deeper look at the pros and cons of both options and how you can deal with the downsides.

Shutting Down Regularly

Shutting down regularly is the practical option, but it's not without its downsides. Let's take a look at the pros, cons, and what you can do to remedy the disadvantages.

Pros

Lower energy costs - Computers can draw a large amount of power, especially if you're running a high-end desktop. Shutting your machine down when it isn't in use will prevent excessive and unnecessary use of power, wasting less energy and saving you money on your electric bill.

Fewer temporary system issues - Those who keep their machines booted up indefinitely are familiar with the little problems that crop up when a computer is in use for a long time. Strange little problems occur and they're often solved by a reboot. If you're essentially rebooting every day, you're giving your machine a fresh start. This helps avoid minor system issues.

Quiet hours - When your machine is running, it's capable of making noise. The sounds of the fans can be bothersome if you're sleeping in the same room, but you also run the risk of the computer playing and alert or other sound unexpectedly. This is easily rectified by muting your sound every night, but you run the risk of forgetting. (Of course, you can automate that process on Windows and OS X pretty easily.)

A longer-lasting machine - While you can never really know when your computer is going to fail, less stress placed on its components will contribute to a longer life. You still have to keep it clean, dust-free, and well-maintained, but less activity can help your hardware last longer.

Cons

Inconvenience - The biggest disadvantage of shutting down and booting up on a daily cycle is that it's inconvenient. You have to get everything in order to shut down each night and wait to start up in the morning. On top of that, if you forget to boot up and need to access your machine while you're, say, at the office, you won't be able to because it's offline. This problem is easily solved by automated the shut down and start up process. Doing so puts your computer on a schedule so you won't have much of an inconvenience at all.

Energy used for nothing - While you certainly save energy by shutting down your machine, it'll still draw power when off. While an operating desktop would draw a lot more, it would, at least, be capable of doing something while you're away. This problem is easily remedied, however, with a power-regulating socket like the Belkin Conserve ($10). Alternatively, if your desktop supports it, you can use it as a USB device charger overnight so that small power draw isn't going to waste.

You can just hibernate instead - Why shut down when you can hibernate? Hibernation draws about as much power and saves the current working state of your machine so you can resume right where you left off. This is a standard operation for Windows machines, but OS X can use it, too. Apple calls hibernation "Safe Sleep," and it's only regularly employed to laptops when the battery levels are critically low. You can enable this feature at will, however, with apps like SafeSleep and SmartSleep. You can also save power by simply sleeping your computer, which has the advantage of waking up faster (although if you're using an SSD that gain is negligible), but the power consumption is considerably higher. To get a specific idea of how your devices consume power in their various modes, check out this comparison table.

Never Shutting Down

Keeping your computer powered on is the more convenient option. It offers a few distinct advantages that can save you a bit of time and frustration, but also has a few major downsides of its own.

Pros

Your machine's always ready to go - It's nice to be able to sit down at your machine and just start working without any setup necessary. Such a luxury comes at a cost—a higher electric bill—but that may be worthwhile depending on your needs.

Your computer can work while you sleep - There are plenty of ways your computer can work while you sleep. It can perform tasks like backup, system maintenance, video encoding, software updates, downloading, uploading, and virtually anything else it can do without your presence. This is a great opportunity to perform intensive tasks when they won't encumber your work.

Cons

Heavy power usage - Running your computer 24/7 draws a lot of power. If there's any reason to turn your machine off with any regularity, it's to avoid wasting resources and saving some money on your electric bill.

Rebooting can be a pain - If you're not accustomed to shutting down regularly, the rare reboot can be pretty annoying. Aside from just feeling more like an inconvenience, you'll never be prepared to shut down. If you have several documents, browser windows, applications, and services running, you probably do not have a process in place to easily suspend everything when necessary. OS X Lion (and Mountain Lion) users have the advantage of the Resume feature, which allows you to restore the computer to the working state it was in before shutting down, but that only works perfectly if all your apps support it. Rebooting isn't some horrible, horrible thing, but it is an inconvenience if you're not used to it.

As you can see, each option has its advantages and disadvantages. What works best for you will depend on your needs.